The raw food people tell us that cooking food destroys its enzymes. “Raw food is better for you,” they say.
Maybe sometimes. But now scientists have learned that cooking can make at least some vegetables better. This is something of great importance to everyone who has diabetes — even those of us who are following a low-carb diet.
New research out of Italy is a culinary shocker. It’s counterintuitive and not as simple and straightforward as we have been led to believe. But then, what is nowadays?
In the new study, a team of five researchers from universities in Parma and Napoli studied what happened to the nutritional content of broccoli, carrots, and zucchini (which they call by its common British name, courgettes) when they were boiled, steamed, or fried. They just reported their findings in the December issue of the Journal of Agricultural and Food Chemistry, which the American Chemical Society publishes. You can find the full-text of the report, “Effects of Different Cooking Methods on Nutritional and Physicochemical Characteristics of Selected Vegetables,” online.
Cooking these vegetables with water — steaming or boiling them — retains their antioxidants better than frying does. For example, steaming broccoli increases its glucosinalates — which may help fight cancer — compared with eating broccoli raw.
They discovered that all three ways of measuring antioxidants showed that more of them are available when they cooked each of these vegetables rather than when we eat them raw. Why? “Probably because of matrix softening and increased extractability,” they write.
The tested vegetables are among those that we sometimes eat raw and sometimes cook. Others that we eat both ways include cabbage, cauliflower, celery, green peppers, mushrooms, onions, and spinach. We already knew that some of the good stuff in tomatoes, lycopene, is more available when we cook them.
On the other hand, I doubt that cooking could improve the living watercress that I bought recently for my salads. I certainly will continue to eat my salad greens raw. But now I will steam my broccoli, carrots, and zucchini. And certainly, if you have digestive problems, it’s important to eat veggies that have been well cooked in water.
Still, this research doesn’t even begin to touch on the real processing of food that occurs in the gut. We have to wonder about how efficient our digestive systems are at extracting these nutrients.
It may be that there is significant enzymatic processing in the intestines that makes the difference in final nutrient absorption of cooked versus raw vegetables negligible. It may also be that when lesser processed foods get to the large intestine, the bacteria there respond by producing more beneficial nutrients that we absorb so we end up getting good nutrition from the veggies either cooked or raw.
This article is based on an earlier version of my article published by HealthCentral.